Submission #226047

#	Time	Username	Problem	Language	Result	Execution time	Memory
226047		quocnguyen1012	Paprike (COI18_paprike)	C++14	100 / 100	76 ms	17532 KiB

paprike

#include <bits/stdc++.h>

#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define eb emplace_back
#define ar array

using namespace std;
typedef long long ll;
typedef pair<int, int> ii;

const int maxn = 1e5 + 5, inf = 1e9;

int N, K, a[maxn];
vector<int> adj[maxn];

pair<ll, int> solve(int u, int p = -1)
{
  vector<pair<ll, int>> child;
  for(int v : adj[u]) if(v != p){
    child.eb(solve(v, u));
  }
  sort(child.begin(), child.end());
  pair<ll, int> res = mp(a[u], 1);
  for(int i = 0; i < child.size(); ++i){
    if(res.fi + child[i].fi <= K){
      res.se += child[i].se - 1;
      res.fi += child[i].fi;
    }
    else{
      res.se += child[i].se;
    }
  }
  //cerr << u << ' ' << res.se << '\n';
  return res;
}

signed main(void)
{
  ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  #ifdef LOCAL
    freopen("A.INP", "r", stdin);
    freopen("A.OUT", "w", stdout);
  #endif // LOCAL
  cin >> N >> K;
  for(int i = 1; i <= N; ++i)
    cin >> a[i];
  for(int i = 1; i < N; ++i){
    int u, v; cin >> u >> v;
    adj[u].eb(v); adj[v].eb(u);
  }
  cout << solve(1).se - 1;
}

Compilation message (stderr)

paprike.cpp: In function 'std::pair<long long int, int> solve(int, int)':
paprike.cpp:27:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i = 0; i < child.size(); ++i){
                  ~~^~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 13 / 13
• Subtask 3: 27 / 27
• Subtask 4: 49 / 49